Material:The PROWHEEL Ebike ISIS crank arms are made of Forged Alloy 6061, Crank Finish is SAND BLACK,this crank arm is sturdy and durable,High strength, high hardness, not easy to deform. Size:This Crank Arm Length is 127MM/140MM/152MM/160MM/165MM/170MM/175MM,A variety of specifications for you to choose.Before purchasing this product, please make sure that the size of this product is consistent with the size you need,This Crank Arm can only be used on electric bicycles. Spindle Interface Type:Compatible with ebike mid-drive motors with the ISIS standard bottom bracket.PROWHEEL produces the international standard ISIS Model crank arm,EB0Q ISIS CRANK ARM's dimensions are in accordance with the ISIS International Standard, the ISIS diameter is approximately 17.464mm. Please measure the ISIS diameter of the crank arm when purchasing. Ebike Applicable Model:Compatible with ebike BOSCH GEN4,YAMAHA PW-X3,YAMAHA PW-X2,PANASONIC GXO,BANGFANG M620,ANANDA M230,OLI M03,OLI M02,VINKA E30,VINKA S20,MOTINOVA MIGIC T1,MIVICE X700,BROSE STANDARD,BORSE MAG. CUSTOMER SUPPORT:Our PROWHEEL team is ready to get in gear and help with any questions or concerns about bike accessories. We are available 24/7 to make sure that your customer journey rides like a dream. ISIS crank